Health & Fitness

Trial vaccine effective in keeping STI at bay


A trial vaccine against chlamydia has been found to be safe and effective in preventing infection of the sexually transmitted disease that affects more than 131 million people globally.

Vaccination may be the best way to tackle the disease, which mostly affects teenagers, young adults and gays.

Chlamydia is the most common sexually transmitted bacterial infection worldwide, but treatment has largely failed to curb the epidemic, a study published in The Lancet Infectious Diseases journal says.

The rising new cases and recurrences have been linked to sharing of sex toys, oral or anal sex and unprotected casual sex.

In a study carried out in Mtwapa Research Clinic in the Coast, researchers found high rates of chlamydia and gonorrhoea of the rectum in men having sex with men.



Of concern is that most chlamydia infections go untreated because many people do not show symptoms, hence they unknowingly pass it on to new partners.

“Given the impact of the chlamydia epidemic on women’s health, reproductive health, infant health through vertical transmission, and increased susceptibility to other sexually transmitted diseases, a global unmet medical need exists for a vaccine against genital chlamydia,” says the study’s author, Prof Peter Andersen, from Denmark.

Despite the disease being symptomless in some people, it is still harmful. For one in every six women infected with chlamydia, the infection travels up from the cervix and causes pelvic inflammatory disease.

This can result in chronic pelvic pain and even infertility or ectopic pregnancy, especially in the poor nations, where access to treatment and screening is limited.

The disease can also be transmitted from a pregnant woman to her unborn baby.

In addition, chlamydia is strongly associated with susceptibility to other sexually transmitted infections, particularly gonorrhoea and HIV, and chlamydia infection during pregnancy can increase the risk of adverse outcomes such as miscarriage, stillbirth and pre-term birth.


In the trial, 35 healthy women demonstrated promising early signs of what could be an effective vaccine, but further trials are required to determine whether the immune response it provokes effectively protects against chlamydia infection.

The next step will be a trial to test the efficacy of the vaccine, which will happen in the next couple of years.

Common symptoms of chlamydia include increase in vaginal discharge or a white, cloudy or watery discharge from the penis, pain when urinating, swelling in the testicles and bleeding in between periods.

Untreated chlamydia can prevent a man from siring a child.